Robotic end effectors having fingers and nails to grasp and cage items

Abstract

Robotic end effectors may include a suction cup, one or more grasping fingers, and one or more flexible nails to securely and reliably engage, grasp, and cage items. The grasping fingers may move between open and closed positions to grasp items. In addition, the flexible nails may be coupled to ends of the grasping fingers to facilitate caging of items by the fingers and nails. For example, the flexible nails may bend, flex, or slide under, around, or relative to items and thereby enable grasping and caging of portions of items by the fingers and nails. The nails may be formed of various materials, with various layers or thicknesses of materials, and/or with variable flexibility or friction properties. Further, the nails may be transitioned or actuated between multiple configurations, including a sliding configuration and a grasping configuration.

What is claimed is: 
     
       1. An item grasping apparatus, comprising:
 a robotic arm; 
 an end effector coupled to the robotic arm, the end effector comprising:
 a suction cup; 
 a plurality of grasping fingers; and 
 a plurality of flexible nails, individual ones of the plurality of flexible nails being coupled to respective ones of the plurality of grasping fingers; 
 wherein individual ones of the plurality of flexible nails include a variable friction along a length of respective flexible nails; and 
 
 a control system in communication with the robotic arm and the end effector, the control system configured to at least:
 instruct, using the suction cup, engagement of an item by the robotic arm and the end effector; and 
 instruct, using the plurality of grasping fingers and the plurality of flexible nails, at least one of grasping or caging of the item by the end effector; 
 wherein the plurality of flexible nails are configured to slide between at least one portion of the item and at least one support surface proximate the item. 
 
 
     
     
       2. The item grasping apparatus of  claim 1 , wherein the control system is further configured to:
 subsequent to the engagement of the item using the suction cup, instruct, using the robotic arm, movement of the item relative to the at least one support surface to facilitate the caging of the item using the plurality of grasping fingers and the plurality of flexible nails. 
 
     
     
       3. The item grasping apparatus of  claim 1 , wherein the plurality of grasping fingers are actuatable between an open position and a closed position. 
     
     
       4. The item grasping apparatus of  claim 1 , wherein the plurality of flexible nails have lower flexibility at respective portions that are coupled to the respective ones of the plurality of grasping fingers, and have higher flexibility at respective ends away from the respective ones of the plurality of grasping fingers. 
     
     
       5. The item grasping apparatus of  claim 1 , wherein the plurality of flexible nails are actuatable between a first, sliding configuration and a second, grasping configuration. 
     
     
       6. A robotic end effector, comprising:
 a suction cup configured to engage an item; 
 at least one grasping finger configured to move between an open position and a closed position to grasp the item; and 
 at least one flexible nail coupled to the at least one grasping finger, wherein the at least one flexible nail is configured to slide relative to the item in a first, sliding position, and is configured to at least one of grasp or cage the item in a second, grasping position; 
 wherein the at least one flexible nail includes a variable friction along a length of the at least one flexible nail. 
 
     
     
       7. The robotic end effector of  claim 6 , wherein the at least one grasping finger comprises a plurality of grasping fingers arranged around the suction cup; and
 wherein the at least one flexible nail comprises a plurality of flexible nails coupled to respective ones of the plurality of grasping fingers. 
 
     
     
       8. The robotic end effector of  claim 6 , wherein the at least one grasping finger is formed of at least one of silicone, rubber, plastic, composite, or metal; and
 wherein the at least one flexible nail is formed of at least one of silicone, rubber, plastic, composite, or metal. 
 
     
     
       9. The robotic end effector of  claim 6 , further comprising:
 an actuator coupled to the at least one grasping finger and configured to move the at least one grasping finger between the open position and the closed position; 
 wherein the actuator comprises at least one of a pneumatic actuator, a servo, a solenoid, a motor, or a shape memory alloy. 
 
     
     
       10. The robotic end effector of  claim 6 , wherein the at least one flexible nail includes a variable flexibility along the length of the at least one flexible nail. 
     
     
       11. The robotic end effector of  claim 10 , wherein the variable flexibility is formed by at least one of different materials, different numbers of layers of materials, or different thicknesses of materials along the length of the at least one flexible nail. 
     
     
       12. A robotic end effector, comprising:
 a suction cup configured to engage an item; 
 at least one grasping finger configured to move between an open position and a closed position to grasp the item; and 
 at least one flexible nail coupled to the at least one grasping finger, wherein the at least one flexible nail is configured to slide relative to the item in a first, sliding position, and is configured to at least one of grasp or cage the item in a second, grasping position; 
 wherein the at least one flexible nail is foldable along a length of the at least one flexible nail; 
 wherein the first, sliding position includes an unfolded configuration of the at least one flexible nail; and 
 wherein the second, grasping position includes a folded configuration of the at least one flexible nail. 
 
     
     
       13. A robotic end effector, comprising:
 a suction cup configured to engage an item; 
 at least one grasping finger configured to move between an open position and a closed position to grasp the item; and 
 at least one flexible nail coupled to the at least one grasping finger, wherein the at least one flexible nail is configured to slide relative to the item in a first, sliding position, and is configured to at least one of grasp or cage the item in a second, grasping position; 
 wherein the at least one flexible nail includes a stiffening rod that extends into or retracts from the at least one flexible nail; 
 wherein the first, sliding position includes a retracted configuration of the stiffening rod relative to the at least one flexible nail; and 
 wherein the second, grasping position includes an extended configuration of the stiffening rod relative to the at least one flexible nail. 
 
     
     
       14. A robotic end effector, comprising:
 a suction cup configured to engage an item; 
 at least one grasping finger configured to move between an open position and a closed position to grasp the item; and 
 at least one flexible nail coupled to the at least one grasping finger, wherein the at least one flexible nail is configured to slide relative to the item in a first, sliding position, and is configured to at least one of grasp or cage the item in a second, grasping position; 
 wherein the at least one flexible nail includes a vibration transducer; 
 wherein the first, sliding position includes a first vibration profile emitted by the vibration transducer; and 
 wherein the second, grasping position includes a second vibration profile emitted by the vibration transducer. 
 
     
     
       15. An item grasping method, comprising:
 determining, by a control system, at least one characteristic of an item; 
 determining, by the control system, a grasp point of the item based on the at least one characteristic; 
 determining, by the control system, an approach trajectory based on the at least one characteristic; 
 determining, by the control system, a grasp characteristic based on the at least one characteristic; 
 instructing, by the control system, movement of a robotic arm having an end effector based on the approach trajectory and the grasp point, the end effector including a suction cup, at least one grasping finger configured to move between an open position and a closed position, and at least one flexible nail coupled to the at least one grasping finger; 
 instructing, by the control system and with the at least one grasping finger in the open position, sliding of the at least one flexible nail relative to the item and at least one support surface; and 
 instructing, by the control system and with the at least one grasping finger in the closed position, grasping of the item by the at least one flexible nail; 
 wherein the sliding of the at least one flexible nail relative to the item and the grasping of the item by the at least one flexible nail are instructed based at least in part on the grasp characteristic. 
 
     
     
       16. The item grasping method of  claim 15 , further comprising:
 receiving, by the control system from an imaging device, imaging data of the item; and 
 processing, by the control system, the imaging data of the item; 
 wherein the at least one characteristic of the item is determined based on the imaging data. 
 
     
     
       17. The item grasping method of  claim 15 , further comprising:
 determining, by the control system, a movement characteristic based on the at least one characteristic; and 
 instructing, by the control system and with the at least one grasping finger in the closed position, movement of the item based at least in part on the movement characteristic. 
 
     
     
       18. The item grasping method of  claim 15 , further comprising:
 instructing, by the control system, engagement of the item by the suction cup of the end effector; and 
 instructing, by the control system, lifting of the item by at least one of the suction cup or the robotic arm to facilitate the sliding of the at least one flexible nail relative to the item and the grasping of the item by the at least one flexible nail. 
 
     
     
       19. The item grasping method of  claim 15 , wherein the grasp characteristic comprises at least one of a grasping type, a grasping sequence, or a grasping force. 
     
     
       20. The item grasping method of  claim 19 , wherein the grasping type comprises at least one of picking, scooping, sliding, pushing, turning or re-orienting the item.